John davis



@uiten taies" gamut ffice..

IMPROVEMENT IN PLANETARIUMS.

'tite ttyehnle imma it in tigen Eaters man mit taking putt 'tf it time.

TO ALL WHOM IT MAY CON CERN Be it known that I, JOHN DAVIS, of the city and county of Allegheny, l.in the State of Pennsylvania, have invented a new and useful apparatus forvrepresenting the axial motion of thpfsun, and the axial and orbital motion of the eight primary planets,"and also the various motions of the satellites around their primaries,

respectively, in different periods, which apparatus I propose calling Planetelles, (which signifies planets and satellites 'and I do hereby declare that the following isa full, clear, and exact description thereof, reference being had to the accompanying drawings, and. to the letters and figures of reference marked thereon.

- The nature of my invention consists in representing,=by the means hereinafter described, the axial motion'- of lthe sun, and the axial and orbital motions of theeightprimary planets, viz, Mercury, Venus, Earth, Mars,

lJupiter, Saturn, Uranus, and Neptune, and also the various motions of the satellites oithe primary planets.

To enable others skilled in the art of constructing philosophical and astronomical instruments and apparatus to make and use my invention, I will proceed to describe its construction and operation. In the accompanying drawings, which form part of my specificationl Figure 1,:sheet A, represents 'a side elevation of my improvement in apparatusffor sliowing the axial motion of the sun, and the axial and orbital motions of the eight primary planets, and also thai-.various motions -of the satellites of the planets.

Figure`2, sheet A, `represents afront elevation of the same. Figure 3, sheet A, represents a section of a partof the mechanism used for representing thealtitude of the moon.

planets, and satellites. Y

Figure 5, sheet B, is a bottom view of a portion of the mechanism used for imparting motion to Jupiter and his satellites. y

K Figure 6, sheet B, is` atop lview of the same. Y:Figure 7, sheet B, is a section of the same.

Figure 8, sheet C, is a section of a portion of the mechanism used for obtaining the desired motions ofthe sun, planets, and satellites.

In .order that the lmechanic may fully andclearly'understandmy invention, I will at first describe and explain the parts represented in gs. 1, 2, and 3.

The planets and satellites are placed out on the end of the hollow arms marked C1 C2 C3 C* C5 C? CT CB. These arms are secured to a number of hollow shafts, marked Dl D2 D3 DAi D D6 D7 DS. The wheels, marked R P B B1 B2 l3 B4 B5, are provided, on the vunder sident' the rim 24, with cogs or teeth, which gear into teeth on wheels placed on'shafts, which are placed within the hollow arms C1 Cz C3 C4 C5 C- 07 C8, and are used, in connection with *gearing placed on the outer ends of the arms and shafts, for the purpose of imparting the axial motion to the planets,'and the desired motion to the satellites, which revolve around their primaries.

A.s the mechanism for imparting the desired motions to the planets will be hereinafter more fully described, I willpowgive a brief explanation of the planets and satellites describing their relation to each other, and the relation of the whole to the sun.

S represents the sun, which rotates on his axis once in about twenty-live (25) days and ten (10) hours..

M represents Mercury, which is the planet nearest to the sun, and rotates on his axis once in about twentyfour (24) hours, and revolves'around the sun once in about eighty-seven (87) clays.

V represents Venus, which is the second -planet out from thesun. She rotates on her axis once in about twenty-four (24) hours, and revolves around the sun once in about two hundred and twenty-five .(225) days, and her axis is iuclined'to the plane'of her orbit at an angle of about seventy-iive (75) degrees.

E represents the earth, which is the third planet, out from the sun, and 4rotates on its axis once in about twenty-four (24) hours, and revolves around the sun once in about three hundred and sixtyfive (365) days, and its axis is inclined to the' plane of its orbit at an angle of about twenty-three and onefthird (23%) degrees.

m represents the earths moon, which rotates'on her axis onceA inA about twenty-seven and one-third` (27%) days, and revolves around the earth about thirteen times while the earth is revolving once around the sun. The

Figure 4, sheet B, represents a section of the mechanism used for obtaining the desired motions of the sun,

plane of the mcons orbit is at an angle of about ve degrees to the plane of the earths orbit; hence, the moon, in revolving around the earth, crosses the plane of the earth's orbit at two points during each revolution, which crossing, in astronomical language, is termed the ascending and descending nodes of the moon, which I represent by the inclined and revolving disk or wheelmarked a, which is revolved in the inclined guide o', placed ou the end of the arm C3, (see figs. 1 and 8.) The moon, m, is securodon the upper end of a rod, the lower end `of which is secured to the inclined disk or wheel o, which is revolved in the guide o by the wheel marked 1.

The rod is held in the desired position by n. guide, 8, which is attached to the rod z', and slides on the rodz, on theuppcr end of which is pivoted the earth, E.- By thus arranging the moon, m, on the inclined disk or wheel o, the inclination of the moons orbit to the plane ofthe earths orbit, and the rctrogrcssion of the moons nodes, are partially represented; but having invented a moreperfect apparatus for representing the various motions of the moon, which apparatus I propose making the subject of another application for Letters Patent, I will therefore, without further description of the moon, m, and its planet, E, proceed to describe the fourth planet 'out from the sun, which is I v Mars, indicated by M. He rotates ou his axis once in about twenty-four (24) hours, and revolves around the sun once in about six hundred and twenty-ve (625) days, andhis axis is inclined to the plane of his orbit at an angle of twenty-seven (27) degrees. n p i J represents Jupiter, which is the fth planet out from the sun. Hel rotates on his axis'once in about ten (10) hours, and revolves around the sun once in about twelve (12) years, and his axis is inclined to the plane of his orbit at an angle of about three degrees. Jupiter has four satellites, 1, 2, 3, and 4, which revolve around him in four different periods of time, varying'frorn about two (2) to aboutseventeeu (17) days.

S represents Saturn, which is the 'sixth planet out from the sun. He rotates on his axis once in about ten `(1G) hours, and revolves around the sun once in about twenty-nine and one-half (29%) years, and his axis is inclined to theplane of his orbit at an angle of about twenty-eight (28) degrees; and around him are rings, which revolve nearly in the plane of his equator, and revolve around him in about ten (10) hours. Saturn has eight satellites, m, e, t, d, r', t1, L, J', which revolve around him in eight different periods `of time, varying from one to about seventy-nine days.

U represents Uranus, Vwhichl rotate on his axis. He revolves around the sun once in about eighty-four (84) years, and has six satellites, o, a, u, t2, 5, 6, which revolve aroundhim from east to west. The period of time required for the satellites of Uranus to make o. revolution around him are not definitely known, nor4 is it known whether he does or does not rotate on his axis. The satellites of Uranus are revolved from eastto west by placing wheel 2, which revolves the disks which revolve the satellites around him, on the linner side from `their axis, which, it willbe observed, dilfers from the position of the same wheel 2 used for revolvingthe disks or wh'eels which revolve the satellites of the other planets.

N represents Neptune, which I also rotate on his axis. He revolves around the sun once in about one hundred and sixty-four (164) years, and is supposed to have two satellites, 1 and 2.v It is not knownthat Neptune rotates on his axis, nor are the periods of time known which are required for his supposed satellites to make a revolution around him. v i

Having thus described the parts represented in figs. 1, 2, and 3, and given the relative motion ofthe planets around the sun, and thelvarious motions of the satellites around their primarios, I will new proceed to describe more fully the mechanism which I use for obtaining said motions in my improved planet-elles. i

In the drawings, A represents the case, in which is enclosed a large portion of the operating-gear. 'The sides A1 and A2 of the case A serve as bearings or supports for the shafts zo wl fw2 B, and the hollow shafts marked DD2 D3 D4, 85e., which are concentric with the shaft B, which shafts, and the relation they bear to each other and to the operating-gear, are clearly shown in lig. .4, sheet B, and fig. 8, sheet C. One 'endfof the shaft fw'* is supported and held in position by the piece marked 21, (see iig. 4, sheet B.) The pieces marked 22, 23and 25, are supports or bearings for the shafts o, o1, and o2 of thc endless screws 11:2, f, Ste. The shaft w is provided with a small wheel, u, which gears into the wheel t on the shaft w1, which is also provided with a wheel, r, which gears into the wheel 13 on shaft wg, on which also are secured permanently the wheels 12, 11, 10, 9, 8, 7, 6, 5, e, d, and hevclled wheels 4, 1, and n. The wheels 5 and G are held firm by braces 30. Y

In tracing out the different whecls,and their connection with each other, and their relation to the several parts, as given in the description which follows, it will he necessary to ,refer back and forward to figs. 4 and 8 of sheets B and C. V y

The wheel 12 gears into the wheel on shaft B, and the wheel 11 gears into the wheel 7i on the hollow shaft Di. The wheel 10 gears into the wheel g on the hollow shaft D2. The wheel Qgears into wheelfon the hollow shaft D3. The wheel 8 gears into wheel e0 on the hollow shaft D. The wheel 7 gears into wheel c8 on the hollow shaft D". 'lhe wheel 6 gears into a bevel-wheel on the shaft o3, which is provided with an endless screw, :0, which gears into wheel e7 on the hollow shaft D". The wheel 5 gears into wheel ne' on the hollow shaft D". The bevel-wheel 4 gears into the wheel 3 on the shaft o, which is provided with an endless screw, c, which gears into the wheel e5 on the hollow shaft D5. The wheel c gears into the wheel con the hollow shaft D. The bevel-wheel 1 gears into wheel 2 on shaft oI provided with an endless sorew,j", which gears into wheel e3 on the hollow shaft D7. The wheel el gears into wheel c2 on the hollow shaft Di. The bevel-wheel nf'geais into the wheel m on shaft o provided with an endless screw, X, which gears into wheel c1 on the hollow shaft D5. Thehollow arm Cs'is secured on the projection, near the outer end of the hollow shaft Dl. The wheel B5 is secured on the hollow shaft D, near its outer end. 'lhc hollow arm C*- is Secured on the projection 10 near the outer end of the hollow shaft D7. The wheel Bi is secured on the hollow shaft Dm, near its outer end. The hollow arm C6 is secured on thc projection 1l, near the outer end of the hollow shaft Dr'. The wheel B3 is secured on the hollow shaft D, near its outer end. The hollow arm C5 is secured on the projection 12, near the outer 

